Model 134—2 PocketCal mA Calibrator is manufactured by the Altek company. The instrument has a source that ranges from 0.00 to 24.00 mA or -25.0 to 125.0%. It has its basic accuracy of ± 0.08% of 24 mA Span + 1 LSD. The speed sensitive digital potentiometer adjusts the output from any QUIK-CHEK position for valve stroking. Power up transmitters drives to 700 ohms loads. Its battery life sources is 12 mA for over 22 hours, 20 mA for over 16 hours. The device has fuseless protection up to 120 V AC/DC. This kind of calibrator is dependable operation.